摘要
用MALDI_TOFMS细菌指纹图谱鉴定细菌 ,建立区分金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株的MALDI_TOFMS分析方法,检测了76株从临床标本中分离得到的金黄色葡萄球菌 ,用软件进行聚类分析,以nuc(耐热核酸酶)基因和mecA(耐药)基因聚合酶链反应(PCR)检测结果为参照 ,74 %的菌株经MALDI_TOFMS给出了正确的鉴定结果;金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株的质谱图有很大差别 ,各自有其特征峰;经过软件聚类分析 ,76株实验菌株划分为敏感群和耐药群;与PCR检测结果对照 ,有7株菌PCR检测mecA基因为阴性 ,而经MALDI_TOFMS鉴定为耐药株 ,表型鉴定表明其中有5株为敏感株;利用细菌指纹图谱和数据库检索对大多数菌株实现了正确鉴定;MALDI_TOFMS分辨率高 ,甚至可以区分株间的差异 ,实现了区分金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株;
To identify the sensitivity and resistance of various Staphylococcus aureus strains to methicillin, intact cells from 76 S.aureus clinical isolates were analyzed by matrix _ assisted laser desorption ionization time _ of _ flight mass spectrometry(MALDI _ TOF MS). The mass spectral fingerprints were incorporated into the user's database and subjected to cluster analysis. Polymerase _ induced chain reactions(PCR) with nuc and mecA genes were employed as a reference for the characterization of MALDI _ TOF mass spectra. About 74% of the isolates have been correctly identified as S.aureus by MALDI _ TOF MS. Significant discrepancies between the spectra of methicillin _ sensitive Staphylococcus aureus(MSSA) and those of methicillin _ resistant Staphylococcus aureus(MRSA) were observed that could be used for their characterization. Based upon cluster analysis, all the clinical isolates have been categorized into two groups, namely, sensitive and resistant groups. In comparison with PCR results, 7 mecA _ negative strains were identified as resistant strains by MALDI _ TOF MS, whereas five of the sensitive strains identified by the conventional susceptibility assay were also confirmed by MALDI _ TOF MS to be sensitive. Most of the strains have been identified correctly with the aid of software that allowed the mass spectral patterns to be searched against those in the database. Owing to its high resolution, MALDI _ TOF MS can differentiate bacteria at the strain level for the discrimination of MRSA and MSSA in the study. The results suggested that MALDI _ TOF MS could be used as a rapid and reliable method for bacterial taxonomy.
出处
《分析测试学报》
CAS
CSCD
北大核心
2003年第1期62-67,共6页
Journal of Instrumental Analysis
